Folding knife



FIG. 1 is a front elevational view showing my new design for a folding knife;

FIG. 2 is a side elevational view thereof, the opposite side being _substantially similar;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a rear elevational view thereof, shown in folded mode with the front view being substantially similar;

FIG. 7 is a bottom plan view thereof, shown in folded mode; and

FIG. 8 is a top plan view thereof, shown in folded mode. 

The ornamental design for a folding knife, as shown and described. 